809439812 has 12 divisors (see below), whose sum is σ = 1426711440. Its totient is φ = 401807976.

The previous prime is 809439811. The next prime is 809439823. The reversal of 809439812 is 218934908.

It is a happy number.

It is not an unprimeable number, because it can be changed into a prime (809439811) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 727358 + ... + 728469.

It is an arithmetic number, because the mean of its divisors is an integer number (118892620).

Almost surely, 2^809439812 is an apocalyptic number.

It is an amenable number.

809439812 is a deficient number, since it is larger than the sum of its proper divisors (617271628).

809439812 is a wasteful number, since it uses less digits than its factorization.

809439812 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1455970 (or 1455968 counting only the distinct ones).

The product of its (nonzero) digits is 124416, while the sum is 44.

The square root of 809439812 is about 28450.6557393674. The cubic root of 809439812 is about 931.9548090966.

The spelling of 809439812 in words is "eight hundred nine million, four hundred thirty-nine thousand, eight hundred twelve".